Use the Stereo Expander effect

The most recent version of Adobe Audition CC has a new stereo imagery effect called Stereo Expander.

I'm going to explain how you work with that effect in this lesson.

To demonstrate this I've got 3 files here that I made from a recording studio session done here in Santa Rosa, California, at the Northern Lights studio.

The vocalist is Laura Lee Christensen.

And she's recorded her voice 4 times to create four-part harmony.

Here's the first line: Here's the four-part harmony over here.

I took those 4 tracks.

And I mixed them together.

In this particular one, I mixed them all to the center channel.

And then I spread them out a little bit in this "four voices-small spread.wav" version.

Then I spread them farther apart in this "four-voices-spread.wav" version.

So inside this one, this is essentially mono.

If you look down here in the VU meter, you'll see that the left and right channels are perfectly lined up.

But you can see that even better by looking at the Phase Analysis panel.

I'm going to go to Window, Phase Analysis.

Here it is here.

Using the Histogram (Log Zoom) view.

So I click on this.

That's showing you it's just dead mono.

Even though it's a stereo signal it says: this is a monaural thing here.

Well, let's just take a look what happens if I have a small spread.

Look at that file.

Notice how it immediately changed there.

Let's watch it by play it.

All right, you can see that it spreads out a bit there.

Now we'll go to the "four-voices-spread.wav", meaning it's going to be wider.

Watch it this time.

If you've got a good stereo setup or you got headsets on, you notice that the left and right channel were full there.

You could hear one voice in one here and one on the other, two other voices to the left and the right of center.

And you can see it show up here as things spread up.

Alright, what I want to do now is use the Stereo Expander on each of these 3 different files.

Let me go back to the "four-voices-centered.wav", and find that effect by going to Effects, Stereo Imagery and Stereo Expander...

Now this is a monaural signal essentially.

It's stereo but it basically acts like a mono signal.

But we're going to try to spread it out anyway.

So inside here, you've got the Center Channel, you can pan this channel left or right.

Then you can expand it. 100 is essentially neutral here.

It's not changed at all.

If you go to the left to make it more monaural, and more to the right you make it wider.

Now this acting more or less like a monaural signal, let's see what happens, if we do that.

I'll move this up so you can see the panel down here. - Let's see what happens.

Barely budges, as if nothing happened.

The only reason it moved left is because this thing's just a little bit left of center there.

If I put it at 0, - try that again...

Doesn't move at all.

So when you've got a stereo signal that is basically set up dead center like this, the Stereo Expander will do nothing for you.

Let's change to a different file here.

I'm going to go down to four voices, spread a little bit, "four-voices-spread.wav" like that.

Let's apply the effect to this one.

So I go to Effects, Stereo Imagery, Stereo Expander...

Move up here like that.

We've got it centered now, but fully wide now.

Let's see what happens this time.

Let me pull this down a bit, so you can work on both things at once.

Here I'm going to turn it off.

Let's watch what happens.

Play it again.

I'm gonna turn it on.

You can see how it bounces to the right and left like that.

We are filling up the left and right channels more.

And now we're spreading the signal up for giving it more of a stereo feel.

So that works pretty well, when the signal is not totally spread to the outside.

It's just a moderately centered up stereo signal-like.

So, I'll spread it out again.

I'm seeing also that it's just a little bit right of center.

So I'm gonna take this guy and slide it just a little bit left.

And see if we get it centered a little bit better here.

Yes, that's probably better.

Maybe a little further left would be fine, but you can see how that works.

Now let's try this thing on something where the stereo is really spread out hard left and hard right.

Open it up, go to Effects, Stereo Imagery and Stereo Expander...

Now we're going to turn it off for a second, so you can see how it looks now.

Now I'll switch it on by clicking this little button there.

And we'll go back to the beginning.

And let's watch what happens here.

Yow, that's not good.

We went out of phase.

We worked it too hard and knocked it out of phase, such that we got kind of a raw feel to it. - Try that again.

When that little red ball goes below the line, it's out of phase.

And you could sort of hear it, I think.

That just didn't sound really clean.

There's just kind of a rough edge to it.

So the Stereo Expander works pretty well if you've got a stereo signal that's not totally spread out, not really hard left and hard right.

You got something kind of toward the middle and it does spread it out.

But if it's all the way to the edges like that, you may push it out of phase.

So that's a quick look at the Stereo Expander effect.